With the continuing demand for smaller feature sizes in the semiconductor industry, 193 mm optical lithography has emerged very recently as the technology to produce devices with sub-100 nm. The use of such shorter wavelength of light requires the bottom antireflective coating (BARC) to reduce the reflection on the substrate and dampen the photoresist swing cure by absorbing light that has been passed through the photoresist. Commercially available antireflective coatings (ARC) consist of both organic and inorganic materials. Typically, the inorganic ARC, which exhibit good etch resistant, is CVD based and is subject to all of the integration disadvantage of extreme topography. The organic ARC materials are applied by spin-on process and have excellent fill and planarization properties, but suffer from poor etch selectivity to organic photoresist. As a result, a material that offers the combined advantages of inorganic and organic ARC materials is highly desired.
This invention pertains to silsesquioxane resins that exhibit antireflective coating properties for 193 nm light. These antireflective coatings can be stripped at the removal stage and the silsesquioxane resins are stable upon storage. In addition, the presence of a hydride group in the silsesquioxane resin is essential for the desired cure properties and strip-ability as a 193 nm ARC material.